1. Field of the Invention
The present invention relates to autonomous laser-powered vehicles. More specifically, the present invention relates to a field-deployable autonomous cryobot for penetrating through ice caps of substantial (e.g., kilometers) thickness to deploy astrobiology science payloads and to enable recovery of the vehicle and its in-situ acquired samples at the conclusion of a mission.
2. Description of the Related Art
U.S. application Ser. No. 13/303,449 (the '449 Application) describes the development of an integrated collection of systems that enable the transmission and effective end-use of very large amounts of optical power (kilowatts to tens of megawatts) over relatively long distances (from a kilometer to as much as one-hundred kilometers or more) to fixed, movable, or mobile platforms operating on the ground, undersea, under ice, in the air, in space, and on other planets. The concept is inherently non-line-of-sight, which allows it to directly bypass severe problems that have plagued efforts to utilize laser power beaming over large distances through the atmosphere, underwater, and over terrain where the receiver is not within view of the optical power source.
The '449 Application previously disclosed, inter alia, a ground-based (or base-of-operations-based) power supply with a chilling system used to provide sufficient electrical power and appropriate coolant to a high power fiber laser directing power into an optical fiber. For the purposes of this discussion “laser power” and “optical power” are used interchangeably to refer to any wavelength of electromagnetic radiation that can be effectively injected into a small diameter fiber (generally less than one millimeter in diameter, but potentially larger) that is fabricated from a material that is optically transparent at the selected wavelength.
One aspect of the '449 Application is power re-conversion to electricity and mechanical power at the far end of the fiber. In several cases described in the '449 Application, a “beam dump” is used where the optical energy carried by the fiber is expanded into a diffuse, divergent or collimated broad beam, and caused to impinge directly or indirectly on a thermal mass capable of withstanding the intense heat that will be produced. The beam dump can be advantageously fabricated from a high temperature refractory material.
It was previously believed that beryllium oxide (BeO) or copper could be used to the beam dump material. However, with regard to beryllium oxide (BeO), toxicity issues and the complexity of the necessary piping precluded this option in the end on the grounds of fabrication problems. Concerning copper as material for the beam dump, it was not available in large billet sizes and similarly could not be cast with the very complex internal channels that are required. The beam dump of the present invention was made using a machined block of T6061 T6 aircraft alloy aluminum and a heat-resistant, photon-absorbing, non-off-gassing coating.
“Heat exchanger,” as used herein, refers to any method of capturing, extracting and transferring of heat from one location (e.g., the core of the beam dump) to a different location (e.g., a Stirling engine adjacent to the beam dump) such that maximum electrical energy can be derived from the photonic energy delivered to the beam dump.